Reciprocatory electric motor



H. L. MCHENRY ETAL 24566,]53 RECIPROCATORY ELECTRIC MOTOR Filed Dec. 22, 1950 Jan. 12, 1954 I 1?: e1 15 g5 16 J 2 1 VENTORS WITNESS: WC 7 /dffiZlf Patented Jan. 12, 1954 RECIPRQQATORY ELECTRIC MOTOR Harland L. McHenry, Sayre, Pa., and Leland 0.

Parker, Elmira, N. Y., assignors to Bendix Aviation Corporation; Elmira Heights, N. Y., a corporation of Delaware Application December 22, 1950, Serial No. 202,162

1 Claim. 1

The present invention relates to a reciprocatory electric motor and more particularly to an electromagnetic device for reciprocating a plunger such as the piston of a fuel pump.

It is an object of the present invention to provide a reciprocatory electric motor which is efficient and reliable in operation while being simple and economical in construction.

It is another object to provide such a device which incorporates simple and effective means for controlling the electromagnet.

It is another object to provide such a device in which all the moving parts of the motor are arranged to have rectilinear motion only, and are balanced so as to be unaffected by accelerational forces lateral to their path of movement.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a vertical substantially midsectional view of a preferred embodiment of the invention showing the parts in idle position;

Fig. 2 is a fragmentary section showing the parts in the positions assumed when the piston approaches the lower end of its stroke.

In Fig. 1 of the drawing there is illustrated a cylinder of non-magnetic material in which is slidably mounted a hollow plunger 2 of magnetic material such as soft iron. The upper position of plunger 2 is defined by a cylindrical stop 3 of suitable material such as fiber. A spring 4 urges the piston upward toward said stop, and means for overcoming the spring and drawing the piston downward is provided in the form of a solenoid 5. Circular pole pieces 6 and 1 are located at the ends of the cylinder 5 and serve to locate the solenoid and the cylinder within a cylindrical housing 8 of magnetic material which serves to complete the external magnetic circuit of the solenoid.

Means for energizing the solenoid 5 is provided comprising a battery 9 which is grounded at H and connected through a switch I2 and a lead Hi to a contact l4 mounted on a resilient blade l5 attached to but insulated from the casing 8 as indicated at It. A second contact ll adapted to cooperate with the contact I4 is connected by a lead l8 to one terminal of the solenoid, the opposite terminal of which is grounded at It to complete the electrical circuit. Means for controlling the contacts l4, ll is provided comprising an electro-magnet 2| which is slidably mounted on the exterior of the cylinder One terminal of the electro-magnet 2| is connected by a lead 22 to the battery lead l3 and the other terminal is 2 grounded as shown at 23 so that the electromagnet is energized continuously as long as the switch I2 is closed.

Electro-magnet 2| is provided with a casing 24" of magnetic material which serves to complete the external magnetic circuit thereof, and is urged upwardly by a spring 25.

In order to utilize this motor as a pump, the casing 8 is provided with an inlet '26 and an outlet 21, and check valves 28 and 29 are mounted in the lower end of the cylinder and the upper end of the plunger 2 respectively.

The contacts l4, H are located below the electro-magnet 2| and are opened by the downward movement of the electro-magnet, and the plunger 2, when in idle position, extends through and beyond the electro-magnet 2| as shown in Fig. 4.

In the operation of this embodiment, closure of the switch l2 causes energization both of the electro-magnet 2| and of the solenoid 5 since the contacts l4, H are closed. Plunger 2 is consequently drawn downward, compressing the spring 4. When the plunger begins to be withdrawn from the electro-magnet 2|, said electromagnet is drawn down thereby against the action of the spring 25 until the casing 24' of electromagnet 2| engages the contact-carrying blade l5 so as to open contacts l4, IT as shown in Fig. 5. The consequent deenergization of solenoid 5 permits the plunger 2 to be moved upwardly on its discharge stroke by the spring 4 until the top of the plunger emerges from the electro-magnet 2 which accordingly is raised by the spring 25 so as to permit contacts l4, H to close, whereupon the operation is repeated.

The downward movement of plunger 2 is preferably limited by a suitable stop member 30 so as to prevent the plunger from moving beyond the zone of flux of electro-magnet 2|.

Although certain embodiments of the invention are shown and described in detail, it will be understood that other embodiments are possible and that various changes may be made in the de sign and arrangement of the parts without departing from the spirit of the invention.

We claim:

In a reciprocating electromagnetic motor a solenoid, a non-magnetic hollow cylinder fixed in the solenoid and projecting therefrom, a piston of magnetic material slidably mounted in the cylinder and projecting therefrom, an abutment limiting movement of the piston away from the solenoid and thus defining its idle position, a spring urging the piston toward the abutment,

ing end of the piston and megabi t l gigeu ithVby.v mutual attraction; means limiting m'ovementoi" the electro-magnet away from; the-solenoid, aspring urging the electro-magnet awayjrbnkthe, solenoid, means for energizing thersolendidrin eluding a pair of normally closed contacts, and

4 means responsive to a predetermined movement of the electro-magnet toward the solenoid for opening said contacts.

HARLAND L. MCI-IENRY. LELAND C. PARKER.

UNITED STATES PATENTS Number Name Date 1,640,742 Wallace Aug. 30, 1927 13033027.- McLaren Apr. 18, 1933 :1..68353 Ra lgcn Apr- 26, 9 2372,06? Dicky et a1. June 7, 1949 %7?;3, 5 June 1 9 

